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Due to the increasingly stricter emission legislation and growing demands for lower fuel consumption, there have been significant efforts to improve combustion efficiency while satisfying the emission requirements. Homogeneous Charge Compression Ignition (HCCI) combined with turbo/supercharging on gasoline engines provides a particularly promising and, at the same time, a challenging approach. Naturally aspirated (n.a.) HCCI has already shown a considerable potential of about 14% in the New European Driving Cycle (NEDC) compared with a conventional 4-cylinder 2.0 liter gasoline Port Fuel Injection (PFI) engine without any advanced valve-train technology. The HCCI n.a. operation range is air breathing limited due to the hot residuals required for the self-ignition and to slow down reaction kinetics, and therefore is limited to a part-load operation area.

Fuel economy of two-wheelers is an important factor influencing the purchasing psychology of the consumer within the emerging markets. Additionally, air pollution being a major environmental topic, there is a rising concern about vehicle emissions, especially in the big cities and their metropolitan areas. Potentially, the relatively expensive engine management systems are providing more features and value in comparison to the carburettor counterpart. The combustion system analysis is carried out on a 125 cm3 motorcycle engine and the subsequent numerical simulation comparing the carburettor and the Electronic (Port) Fuel Injection which provides a basis to establish the fuel consumption benefit for the electronic injection systems [1].

Equipping low cost two-wheelers with engine management systems (EMS) enables not only a reduction of emissions but also an improvement in fuel consumption and system robustness. These benefits are accompanied by initially higher system costs compared to carburetor systems. Therefore, intelligent software solutions are developed by Bosch, which enable a reduction of the necessary sensors for a port fuel injection system (PFI) and furthermore provide new possibilities for combustion control. One example for these intelligent software solutions is a model based evaluation of the engine speed. By use of the information contained in the engine speed signal, characteristic features like air charge, indicated mean effective pressure (imep) and combustion phasing are derivable. The present paper illustrates how these features could be used to reduce the system costs and to improve fuel consumption and system robustness.

This paper presents the development of a novel direct coil cooling approach which can enable high performance for electric traction motor, and in further significantly reduce motor losses. The proposed approach focuses on bypassing critical thermal resistances in motor by cooling coils directly in stator slots with oil flow. Firstly, the basic configuration and features are shown: sealed stator slots to air gap, pressure reservoirs on both side of the slots and slot channels for oil flow. The key to enhance thermal performance of the motor here is based on introducing fluid guiding structure in the slot channels. Next, heat transfer in the channel with guiding structure is investigated by CFD and compared with bare slot channel without guiding structure. For studying the effectiveness of proposed cooling concept, numerical analysis is conducted to compare it with HEV favored oil impingement cooling.

Due to the new CO2 targets for vehicles, electrification of powertrains and operation strategies for electrified powertrains have drawn more attention. This article presents a predictive multi-objective operation strategy for hybrid electric vehicles (HEVs), which simultaneously minimizes the fuel consumption and the cycle aging of traction batteries. This proposed strategy shows better performance by using predictive information and high robustness to inaccuracy of predictive information. In this work, the benefits of the developed operation strategies are demonstrated in a strong hybrid electric vehicle (sHEV) with P2-configuration. For the cycle aging of a lithium-ion battery, an empirical model is built up with Gaussian processes based on experimental data.

Environmental consciousness and tightening emissions legislation push the market share of electronic fuel injection within a dynamically growing world wide small engines market. Similar to automotive engines during late 1980's, this opens up opportunities for original equipment manufacturers (OEM) and suppliers to jointly advance small engines performance in terms of fuel economy, emissions, and drivability. In this context, advanced combustion system analyses from automotive engine testing have been applied to a typical production motorcycle small engine. The 125cc 4-stroke, 2-valve, air-cooled, single-cylinder engine with closed-loop lambda-controlled electronic port fuel injection was investigated in original series configuration on an engine dynamometer. The test cycle fuel consumption simulation provides reasonable best case fuel economy estimates based on stationary map fuel consumption measurements.

Due to the EU6 emission standard that will be mandatory starting in September 2014 the particulate emissions of GDI engines come into the focus of development. For this reason, soot and the mechanisms responsible for the soot formation are of particular importance. A very significant source of particulate emissions from engines with gasoline direct injection is the wall film formation. Therefore, the analysis of soot emission sources in the CFD calculation requires a detailed description of the entire underlying model chain, with special emphasis on the spray-wall interaction and the wall film dynamics. The validation of the mentioned spray-wall interaction and wall film models is performed using basic experimental investigations, like the infrared-thermography and fluorescence based measurements conducted at the University of Magdeburg.

General Motors' 3.6L DOHC 4V V6 engine has been upgraded to provide substantial improvements in performance, fuel economy, and emissions for the 2008 model year Cadillac CTS and STS. The fundamental change was a switch from traditional manifold-port fuel injection (MPFI) to spark ignition direct injection (SIDI). Additional modifications include enhanced cylinder head and intake manifold air flow capacities, optimized camshaft profiles, and increased compression ratio. The SIDI fuel system presented the greatest opportunities for system development and optimization in order to maximize improvements in performance, fuel economy, and emissions. In particular, the injector flow rate, orifice geometry, and spray pattern were selected to provide the optimum balance of high power and torque, low fuel consumption, stable combustion, low smoke emissions, and robust tolerance to injector plugging.

The development of future engine generations for Gasoline Direct Injection requires sophisticated combustion systems to reach reduced fuel consumption and future emission standards. The design process of these combustion systems has to be based on a fundamental knowledge of the interacting mixture preparation mechanisms. Beside the air motion inside the cylinder mixture preparation is mainly feeded by the fuel spray quality, injector performance respectively. The article therefore presents a fundamental analysis of the GDI mixture preparation and affords an insight into the injector development. Comprehensive experimental studies were performed in high pressure/temperature vessels using Phase Doppler Anemometry, Laser Induced Fluorescence and video techniques to define the significant fuel spray features for GDI. CFD-calculations were additionally applied to study the temporal behavior of the mixture preparation under injection parameter variation.

1 High precision high pressure diesel common rail fuel injection systems play a key role in emission control, fuel consumption and driving performance. Deposits have been observed on internal injector components, for example in the armature assembly, in the slots of the piston and on the nozzle needle. The brownish to colourless deposits can adversely impact driveability and result in non-compliance with the Euro 4 or Euro 5 emission limits. The deposits have been extensively studied to understand their composition and their formation mechanism. Due to the location of these deposits, the influence of combustion gas can be completely ruled out. In fact, their formation can be explained by interactions of certain diesel fuel additives, including di- and mono-fatty acids. This paper describes the methodology used and the data generated that support the proposed mechanisms. Moreover, approaches to avoid such interactions are discussed.

Direct gasoline injection is one major approach in reducing fuel consumption to fulfill the stages of CO2 reduction commitments in Europe from today until 2008. One effort is to unthrottle the gasoline engine during idle and partial load utilizing charge stratification. This may be realized by using different combustion concepts. This paper shows the analysis of mixture preparation for three different types of direct injected gasoline engines. Each engine was driven with two injectors which have two different atomization concepts. The engine types draw a clear dividing line between their combustion concepts. The injectors were analyzed in a pressure chamber, in an optical engine, and in an actual 1-cylinder engine. The formation of wall-film in wall-guided combustion systems will be discussed. Several important injector and engine parameters for fuel direct injection are pointed out.

In the automotive industry, a steadily growing number of mono-functional electronic control units (ECUs) with increasing complexity on the one hand and restrictive requirements for power consumption and mounting space on the other hand are forcing changes in car electronics. This tendency is enforced by increasing requirements on security, comfort, fuel consumption and emission. In luxury cars, we are now at up to 80 more or less independent electronic units with low potential for synergies between functions (pan-functional services). The actual assembly of electronic units is certainly easily expandable, has very low error propagation but it also involves lots of logistic and bulky cabling with unwanted weight as well as extensive space and power consumption. If trends are properly interpreted, synergies between functions for more comfort, additional safety and security as well as minor air pollution are required in the future at least at unchanged costs in the vehicle's electronics.

A major trend in modern vehicle control is the increase of complexity and interaction of formerly autonomous systems. In order to manage the resulting network of more and more integrated (sub)systems Bosch has developed an open architecture called CARTRONIC for structuring the entire vehicle control system. Structuring the system in functionally independent components improves modular software development and allows the integration of new elements such as integrated starter/generator and the implementation of advanced control concepts as drive train management. This approach leads to an open structure on a high level for the design of advanced vehicle control systems. The paper describes the integration of the spark-ignition (SI) engine management system (EMS) into a CARTRONIC conform vehicle coordination requiring a new standard interface between the vehicle coordination and the EMS level.

The present paper concentrates on the option of catalytic autothermal reforming of gasoline for fuel cell applications. Major parameters of this process are the “Steam to Carbon Ratio” S/C and the air to fuel ratio λ. Computations assuming thermodynamic equilibrium in the autothermal reactor outlet (ATR) were carried out to attain information about their proper choice, as failure in adjusting the parameters within narrow limits has severe consequences on the reforming process. In order to quantify velocity distribution just ahead the catalyst and to evaluate mixing uniformity we designed an ATR featuring an optical access: Thus flow visualization using PIV (Particle Image Velocimetry) and LIF (Laser Induced Fluorescence) technique is possible. Preliminary PIV-results are presented and compared with CFD computations (Computational Fluid D ynamics).

In order to reduce the spark-ignition engine exhaust-gas emission and fuel consumption, it is essential that the required air/fuel ratio is maintained under all operating conditions. An important contribution to this claim is delivered by the injection valve by metering the fuel precisely and producing fine atomization. In this report experimental methods to get specific measuring information and methods for optimizing flow in injection valves are described. Original valves as well as large-scale models were used for the investigations concerning the steady and unsteady-flow characteristics, and were equipped with a number of different sensors. Holograms of the short-time recording of the spray cone are generated and used for the quantification of the atomization quality when injecting into atmospheric pressure and into vacuum, thus complying with the conditions encountered in the engine intake-manifold.

Compressed Natural Gas (CNG) is a promising alternative fuel for internal combustion engines as its combustion is fuel-efficient and lean in carbon dioxide compared to gasoline. The high octane number of methane gives rise to significant increase of the thermodynamic efficiency due to higher possible compression ratios. In order to use this potential, new stratified mixture formation concepts for CNG are investigated by means of numerical fluid simulations. For decades RANS methods have been the industry standard to model three-dimensional flows. Indeed, there are well-known deficiencies of the widely used eddy viscosity turbulence models based on the applied Boussinesq hypothesis. Reynolds stress turbulence models as well as scale resolving simulation approaches can be appealing alternative choices since they offer higher accuracy. However, due to their large computing effort, they are still mostly impractical for the daily use in industrial product development processes.

Meeting current exhaust emission standards requires rapid catalyst light-off. Closed-coupled catalysts are commonly used to reduce light-off time by minimizing exhaust heat loss between the engine and catalyst. However, this exhaust gas system design leads to a coupling of catalyst heating and engine operation. An engine-independent exhaust gas aftertreatment can be realized by combining a burner heated catalyst system (BHC) with an underfloor catalyst located far away from the engine. This paper describes some basic characteristics of such a BHC system and the results of fitting this system into a Volkswagen Touareg where a single catalyst was located about 1.8 m downstream of the engine. Nevertheless, it was possible to reach about 50% of the current European emission standard EU 4 without additional fuel consumption caused by the BHC system.

The worldwide stricter emission legislation and growing demands for lower fuel consumption require for significant efforts to improve combustion efficiency while satisfying the emission quality demands. Homogeneous Charge Compression Ignition (HCCI) on gasoline engines provides a particularly promising and, at the same time, challenging approach, especially regarding the combustion mode switch between spark-ignited (SI) and gasoline HCCI mode and vice-versa. Naturally aspirated (n.a.) HCCI shows considerable potential, but the operation range is air breathing limited due to hot residuals required for auto-ignition and to slow down reaction kinetics. Therefore it is limited to part-load operation. Considering the future gasoline engine market with growing potentials identified on downsized gasoline engines, it is imperative to investigate the synergies and challenges of boosted HCCI.

Stricter emissions legislation and growing demands for lower fuel consumption require significant efforts to improve combustion efficiency while satisfying the emission quality demands. Controlled Homogeneous Charge Compression Ignition (HCCI) combined with boosted air systems on gasoline engines provides a particularly promising, yet challenging, approach. Naturally aspirated (NA) HCCI has already shown considerable potential in combustion efficiency gains. Nevertheless, since the volumetric efficiency is limited in the NA HCCI operation range due to the hot residuals required to ignite the mixture and slow down reaction kinetics, only part-load operation is feasible in this combustion mode. Considering the future gasoline engine market with growing potentials identified in downsized gasoline engines, it becomes necessary to investigate the synergies and challenges of controlled, boosted HCCI.

The stricter worldwide emission legislation and growing demands for lower fuel consumption and CO2-emission require for significant efforts to improve combustion efficiency while satisfying the emission quality demands. Ethanol fuel combined with boosting on direct injection gasoline engines provides a particularly promising and, at the same time, a challenging approach. Brazil is one of the main Ethanol fuel markets with its E24 and E100 fuel availability, which covers a large volume of the national needs. Additionally, worldwide Ethanol availability is becoming more and more important, e.g., in North America and Europe. Considering the future flex-fuel engine market with growing potentials identified on downsized spark ignition engines, it becomes necessary to investigate the synergies and challenges of Ethanol boosted operation. Main topic of the present work focuses on the operation of Ethanol blends up to E100 at high loads up to 30 bar imep.